I'm originally from Chicago, IL, and my evo is tuned to 93 octane, and I now live in California do I need to retune it to 91 to avoid any issues? Or can I run 91 safely and if needed with octane booster?

 

It would be best to get a retune especially if it's 91 from Arizona, California, or Nevada

 

Sorry forgot to mention that I moved to Cali, should i retune it to 91?

 

Yes, definitely. ACN 91 is the worst form of 91 there is. It shouldn't even be considered 91 in all honesty.

 

Hmm, alright and octane booster is no good correct?

 

Mehhh I wouldn't even bother.

 

Okay, thanks understood! In the mean time, drive reg on 91 until I don't get a tune and don't hit boost prob right?

 

Yeah I would go easy on the car, no WOT pulls.

 

Would you recommond doing a full e85? Or not worth it, I'm a full bolt on evo 9 mr.

 

I am a huge advocate for E85. It really wakes the car up. Just make sure you have 1000cc injectors or bigger and at least a walbro 255.

 

Already have that fuel pump installed!
I think I might do e85, thanks for the advice!

 

If you're thinking about switching to anything E85 is definitely the way to go. More power and a bigger knock threshold really helps out. You could run 91 but I'm not sure how "safe" I would consider it. One tank of bad fuel could make you go up in smoke real quick. I wouldn't trust octane boosters either. Definitely baby it though if you are running 91 on your 93 tune.

Plus small changes and you can run e85 in no time. Like stated bigger injectors and a pump that can push the extra fuel. Lines aren't really an issue till you start running big time boost.

 

One thing people fail to mention is that if you do E85, you may want to switch bank to regular pump every 3-4 months to prevent gunk build up.

 

Not entirely necessary. Been running strictly E85 for 3 years now with no issues.

 

Apologize and I am not trying to thread jack but I had a side question that's been bugging me.

Right now I have a 93 tune saved on my accessport. I will be going on a road trip to Kansas later this year and I don't think they will have 93 octane available. I'm hoping to go E85 later this year so a 91 tune is out of the question for my wallet at this time.

If I fill up with a tank of 91 when I get to KS, will driving around out of boost for a week while i'm in KS be OK for my car? or would most people say don't do this.